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The whole idea of these hashing algorithms is that the password is never stored anywhere in plaintext and the hashed version cannot be used to authenticate. Md5 works one way only, as Azmeen pointed out. There aren't many two way algorithms out there, and the few available do little but obfuscate the data (shift cyphers, for example). The thing about md5 is that the md5 hash value will always be the same so you can calculate the hash when data is first entered and compare it against hashed user input later to verify matches.